In fact, according to the content of chromium and nickel ,they are all 304 stainless steel, the composition is containing 18% chromium (Cr), 8% nickel (Ni), but the main difference is the percentage of carbon between them.

304, 304L, 304H chemical composition (%) table

304L is ultra-low carbon stainless steel, the carbon content is down to 0.03% or less, to avoid intergranular corrosion, and the effect of stress corrosion resistance is better than 304 in theory, but in practice the effect is not obvious. Reducing the carbon and adding titanium can achieve the same effect, but adding titanium which is 321 stainless has higher smelting costs, the price is more expensive.

304H , the H refers to the high temperature, high carbon content makes sure it can meet the high temperature requirements, GB150 (A Chinese standard)requires austenitic steel with 525 degrees or higher, the carbon content of should not be less than 0.04%, their high temperature strength is better than pure austenite.

Among the three, 304H has the highest carbon content, 304L has the lowest carbon content, and 304 stainless steel carbon content is in the middle. The higher the carbon content, the worse the corrosion resistance of stainless steel is, also easier to rust. The difference in carbon content also causes the price to vary. As we always said, the application is different, the requirements is different correspondingly.

From the analyses, you can see that the idea 304L can replace the use of 304 is wrong. Whether it can replace or not, should be subject to its application situation, and in accordance with production standards, that is what our sales man should always remember.

If you are interested in this topic, please contact our technical staff to discuss, if you are interested in our stainless steel seamless tubes products, please get in touch with our sales staff, we can produce general purpose 304 / 304L seamless stainless steel tubes, which is widely used In the oil pipeline, heat exchanger, hydraulic tubing etc, also we produce 304H and 321 seamless stainless steel tubes, which is widely used for boiler tubes.